Britney Spears wants duet with Bieber's ex

Britney Spears says Selena Gomez is welcome to do a duet with her anytime. Photo / AP

Britney Spears says Selena Gomez can duet with her any time.

The pop princess took to her Twitter page after viewing a YouTube video showing Gomez covering the song Baby One More Time.

Gomez and her Spring Breakers co-stars Ashley Benson and Rachel Korine sung the song during a SXSW press conference to promote the film.

"Awww @Selenagomez can duet with me anytime," tweeted Spears while posting a link to the YouTube clip.

"PS- I heard @springbreakers is AAA-MAZING! Can't wait to see it!"

The girls sang along to a karaoke version of the tune on a big screen at the Texas press conference in response to a question asking if they were lip-syncing to another Britney number in the film, reports British newspaper The Mirror.

Vanessa Hudgens and James Franco also co-star in the movie about a group of college girls who get into hot water after going on a crime spree to fund their spring break.

The adult drama is a deliberate departure for Gomez, who acknowledges she has a young fan base.

"I was getting kind of repetitive in terms of the roles I was picking, and I really wanted to do something that was completely different," she recently told Interview magazine.

"I want to be taking myself seriously as an actress, and this was definitely a stretch.

"I mean, I'd never smoked a cigarette before in my entire life. It was really funny - they had to show me how to do it."